This invention relates to curable resin systems and, in particular, to polyester resin systems which are suitable for use as laminating resins and, for example, in use with reinforcing webs, such as fiberglass, for the repair of boat hulls, automobile fenders or the like.
Polyester resin systems are already used to patch and repair numerous articles. In general, such systems will be two-component systems. A curable resin will be the primary ingredient of one component. The other component will comprise a so-called curing agent which will, on mixing with the first component, react with the resin to cause a chemical reaction whereby the resin is converted from a pliable mass to a hard solid having structural integrity.
In the past, peroxide-cured systems have generally required temperatures of about 60.degree. F. or higher to cure in an acceptable time. The practicality of using such systems diminishes rapidly as the temperature drops below 60.degree. F. From a practical point of view, this means that one often required a heated garage or the like to repair automobiles and boats with prior art resin systems.
There are available curing systems that would be effective at lower temperatures. For example, some amines can be added as promoters to the resin to lower the curing temperature of the systems. However, these amine-promoted systems must be handled with extreme care. If, for example, the amine promoter is mistakenly added to the peroxide curing agent before adding the mixture to the resin, a severe exotherm can result. For this reason, many consider that amine-promoted systems are not generally suitable for use by the general public.
Consequently, there has remained a need for a safe polyester curing system which can be used at low temperatures.